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32 Cards in this Set
- Front
- Back
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look at neuro quiz 1 too! |
look at neuro quiz 1 too! |
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what is a neuron? |
a eukaryotic cell: clearly defined nucleus and enclosed in a membrane |
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dendrites |
branches on the cell body that receive from other neurons. -the dendrites themselves receive these messages |
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how do the dendrites receive these? |
receive either by excitatory ( speed up) or inhibatory (slow down signals) -excitatory and inhibatory signals are also called action potentials |
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axons |
single process extends from the cell body and transmits messages to other neurons |
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where do the messages travel? |
travel down the axon to its end (called the axon terminal) -this axon terminal is where synapses occur |
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what is a synapse? |
a synapse is a junction or cleft where cells meet and interact with each other. -it is a space between cells where electrical and chemical signals must pass! |
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Neurotransmitters |
-these electrical and chemical signals are called neurotransmitters |
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where do neurotransmitters come from? |
come from pre synaptic area (which is on axon) they are received in the post synaptic area (on the dendrite) -here they bind to specific receptors made for them |
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what are axons wrapped in? |
many are wrapped in myelin -a protective sheath that surronds axon and provides additional boost to signal |
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unmylinated? |
called Nodes of Raviener |
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Action Potential definition: |
change in voltage that occurs because of mylinated and unmylinated interacting -mylinated transfer faster than unmylinated (therefore Nodes slower) |
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electrical potential definition: |
the difference in voltage inside verses the outside
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what happens when there is no signal? |
Neuron is in a resting state |
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ion definition |
a charged particle |
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NA- K pump |
when a neuron receives a signal sodium channels in the membrane are opened and allow an influx of positive sodium ions into the cell, which causes depolarization ( when a negative or positive state is changing so no longer in balance) or the reduction in charge across a membrane |
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Synaptic Transmission: |
The transfer of a signal from the axon terminal to the next cell -signals are trasfered via neurotransmitters |
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common chemical neurotransmitters |
>amino acids >biogenic amines >neuropeptides >acetocholine |
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once neurotransmitters released into the synaptic cleft any remaining neurotransmitters must be removed by: |
1. reuptake of the presynaptic area 2. enzymatic breakdown in the synaptic cleft 3. diffusion
* all to prevent further signal activity |
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how do electrical and chemical synapses differ? |
electrical synapses are not seperated by junction/synaptic cleft -in these signals there is a gap junction which has neuronal membranes touching each other |
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Glial cell (neuroglial cells) |
provide support for the nervous system >part of the role in the BBB is to destroy pathogens |
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3 types of glial cells |
1. astrocytes 2. microglial 3.oligiodendrocytes |
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astrocytes |
Star shaped glial cells -part of BBB- prevents undesirable vessels from entering brain |
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microglial (phagocytes) |
important when tissue is damaged because destroy pathogens and clean up dead cells in tissue -their job is to repair |
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oligodendrocytes |
create myelin sheaths around axons of neurons in the CNS |
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interconnectivity |
all neurons are interconnected -a typical coritcal neuron has 1000-5000 synapses *each synapse is only a few synapses away from any other neuron and each makes a small contribution to overall functioning |
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corticortical connections |
connections between two cortical regions |
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neural circuits |
groups of interconnected neurons |
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thalmocortical connection |
originates thalmus and ends in the cortex |
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corticalthalmic connection |
originates cortex and ends in the thalmus |
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Peripheal Nervous System |
-Somatic (voluntary) -Autonomic (involuntary) -divided into sympathetic and parasympethetic |
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Autonomic |
-controls fight or flight response
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